1.1 This standard extends the application of steel casting reference radiographs E446, E186, and E280 to ductile iron castings when determined appropriate for specific applications (see Section 4). 1.2 The reference radiograph films are an adjunct to E446, E186, or E280, and must be purchased separately from ASTM International, if needed (see 2.1). Categories and severity levels for each discontinuity type represented by these reference radiographs are described within each applicable standard above. Note 1 -The basis of application for these reference radiographs requires a prior purchaser supplier agreement of radiographic examination attributes and classification criterion as described in Sections 4, 5, and 6 of this standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.